Columnar epithelia exist in the lungs, kidneys, bladder, bile ducts, pancreatic ducts, gall bladder, testicles, thyroid, trachea, intestine, stomach, and liver. In many disease states, polymorphonuclear leukocytes (PMN) migrate across these epithelia. (Yardley J. H., et al. (1977). In The Gastrointestinal Tract. Yardley and B. C. Morson, editors. Williams and Wilkins Co., Baltimore. 57.) (Yardley, J. H. (1986). In Recent Developments in the Therapy of Inflammatory Bowel Disease. Proceedings of a Symposium. Myerhoff Center for Digestive Disease at Johns Hopkins, Baltimore. 3-9.) This migration of PMN is an early event in the mechanism of epithelial perturbation, which includes one or more of the following events: abnormal fluid and electrolyte transport, specific epithelial barrier dysfunction, and ultimately mucosal breakdown. These perturbations lead to chronic and episodic inflammatory conditions.
Epithelial perturbations cause or contribute to many inflammatory disease states including: gastritis, diverticulitis, cystic fibrosis, infectious colitis, bronchitis, asthma, Crohn's disease, nephritis, alveolitis, intestinal ulcers, idiopathic AIDS enteropathy, gastroenteritis, ischemic diseases, and glomerulonephritis. The efficacy of existing therapy for epithelial inflammation, such as methotrexate or corticosteroids, is highly unsatisfactory, partially due to a high toxicity which produces severe, adverse effects such as bone-weakening and systemic immunosuppression. (Physician's Desk Reference (41 st ed., 1987) Medical Economics Co., Inc. 1103-1104.) Even under ideal bioavailability conditions, the existing treatments fail to mechanistically target columnar epithelial inflammation.
New treatments for epithelial inflammation are needed.